Opponents of the large-scale Harmony housing development are expected to make their case against the project in court this week. A hearing is set for Friday, April 6.

Filed in September 2016 by the Center for Biological Diversity, the San Bernardino Valley Audubon Society and the Greenspot Residents Association, the lawsuit aims to pause or even stop the master planned community outside Highland. Opponents claim the project violates the California Environmental Quality Act and will have a significant impact on air pollution and flooding.

The project, led by Upland-based developer Lewis Group of Companies, would bring more than 3,600 homes and additional amenities, such as a fire station and trails, to 1,657 acres of land north of Mill Creek, south and west of the San Bernardino National Forest and east of Greenspot Road.

The suit claims the project’s location on the remote outskirts of Highland means that “the 12,000 future Harmony residents who will need to drive daily to jobs in the city’s center or beyond will add hundreds of thousands of vehicle miles per year,” resulting in emissions in excess of regional targets.

In court documents, the city says the final Environmental Impact Report “fully complies with the requirements of the California Environmental Quality Act” and that the suit’s conclusions fail “to overcome the substantial evidence in the record.”